<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width,initial-scale=1.0">
  <title>index</title>
</head>
<body>
<div id="app">

  <ul>
    <li v-for="user in userList">姓名: {{user.username}}, 年龄: {{user.age}}</li>
  </ul>

  <ul>
    <!--关键字,必须是index-->
    <li v-for="(user,index) in userList">序号: {{index+1}}, 姓名: {{user.username}}, 年龄: {{user.age}}</li>
  </ul>

</div>
<script src="vue.js"></script>
<script>
  new Vue({
    el: '#app',
    data() {
      return {
        userList: [
          {username: 'haha', age: 28},
          {username: 'heihei', age: 38},
          {username: 'hoho', age: 18},
          {username: 'xiuxiu', age: 48},
          {username: 'biubiu', age: 88}
        ]
      }
    }
  })
</script>
</body>
</html>